lipofuscin

noun

li·​po·​fus·​cin ˌlip-ə-ˈfəs-ᵊn  ˌlīp-ō- 

-ˈfyü-sᵊn

: a usually yellowish brown, pigmented, insoluble granule that contains protein and lipid and accumulates in cells (as of the heart, liver, or brain) as part of the normal aging process or sometimes in association with diseased states

These pigments, also known as lipofuscins, are thought to be the waste products of oxidative metabolism, and they are stored within each cell of the body and accumulate with time.

—Stephen Nicol, BioScience

see lipofuscinosis